From designer Vaclav Obsivac, the six pieces of this puzzle are painstakingly handcrafted from four different types of wood. (Each puzzle is unique, so coloring may vary.)
You may Try 3 (Tri) challenges:
1 - Uni-Cycle: Simply form a cube (easy)
2 - Bi-Cycle: Each corner of the cube must be one single color (trickier)
3 - Tri-Cycle: The cube must have no identical color touching anywhere, not even diagonally or on an edge (a little more thought required...)
Only 5 left!